When children talk, they gesture and these gestures serve as an index of the child's readiness-to-learn. Work during the current grant period has shown that gesture does more than reflect thought--it plays a role in changing thought and, as a result, contributes to the learning process itself. The purpose of the proposed research is to explore the mechanism underlying this effect--specifically, whether gesture's impact on learning stems, at least in part, from its grounding in action and, if so, whether educators can capitalize on gesture's closeness to action to promote learning. The research has four aims. (1) To explore whether gesture and action work equally well to promote learning, Studies 1-4 manipulate whether children experience action (e.g., rotating an object) or gesture for that action (e.g., gesturing rotate) during training, and observe the effect of that manipulation on learning. (2) To explore whether gesture's closeness to action affects how well it promotes learning, Studies 5-8 manipulate whether children experience concrete gesture (e.g., rotate with the hand shaped as though it were actually moving the object) vs. abstract gesture (e.g., rotate with a pointing handshape) during training, and observe the effect of that manipulation on learning. (3) To explore whether concrete gesture serves as a stepping-stone to abstract thinking, Studies 9-12 manipulate the order in which children experience concrete and abstract gestures, and observe the effect of the manipulation on learning. (4) To explore whether gesture can hinder as well as help learning, Studies 13-16 provide children with gestures containing action features that are incompatible with the task, and observe the effect of incompatible gestures on learning. It is likely that the degree to which gesture resembles action has a larger or smaller effect on learning depending on the concreteness of the task to be learned. As a result, each series of studies uses two types of tasks--a task involving mental manipulation of concrete objects (mental rotation of parts of an object) and a task involving mental manipulation of symbolic objects (mathematical equivalence). In addition, because of the tight link between perceiving an action and performing the action, each series of studies varies whether the child produces gesture or action, or watches an experimenter produce gesture or action. Gesture is often used by children with impairments in language learning to compensate for their disabilities. Understanding the mechanism by which gesture promotes learning may be beneficial in both classroom and one-on-one tutorial situations, particularly in situations where acting directly on objects is not practical.